Laminated glass



June 4, 1935. J. c. ZOLA 2,003,330

LAMINATED GLASS Filed Feb. 17, 1934 J WATER -$OLUBL czmmr cnLuLos: mrRA-r:

um 80LU8LE ccnzm- GLASS INVENTOR Patented Jll ne 4f193 i v p g 2 003 UNITED STATES PATENT John C. Zola, Tarentum, Pa., assignorto Duplate Corporation, a corporation of Delaware 4 Application February 17, 1934, Serial No. 711,701

' 4 Claims. (Cl. 49-81) The invention relates to laminated glass, and plasticizer may vary within a considerable range. particularly to laminated glass in which cellulose In all such cases, ordinary water soluble cements, nitrate plastic of a particular type is used as the such as gelatin and casein, lose most of their efreinforcing sheet. The adhesive used in order fectiveness in adhering the plastic to form safety 5 to cement the glass to ordinary cellulose nitrate glass, and the modified cement, *as hereinafter 5 plastic is in nearly all cases a water solution which described, provides a substitute which has all the comprises gelatin as its essential cementing agent. holding power and effectiveness of gelatin when Another water soluble adhesive which forms a used withordinary cellulose nitrate plastic. satisfactory cement is casein. These water sol- The compounds which I have found effective ubie cements, and particularly the gelatin, are to use with the gelatin or other water'soluble ce- 10 much superior to any other adhesives which have merits in order to make them commercially satisas yet been found for use with ordinary cellulose factory, when used with cellulose nitrate plasnitrate which contains camphor as its-primary ticized as above described, are one of the ethers plasticizer, but when this plasticizer is displaced derived from alcohols having three hydroxyl radto a large extent. 0 entirely. plasticizers which icals. ,Two of such ethers which I have found 15 are water repellent and give the plastics relamost effective are diglyceryl ether and monotively high strength at low temperatures, such as a'cetyl diglyceryl ether. A typical formula of dibutyl phthalate or diamyl phthalate, the gelathe cement is as follows: tin and other water soluble adhesives lose their effectiveness as cements. This is apparently due Gelatin 2g? 2 to the factthat the plastic (having now a high Water moisture resistance) will not take up or absorb Dlglyceryl ether enough moisture from the adhesive to keep the The percentage f ingredients may be varied films of such adhesive which are deposited on within a considerable range Th ether may be the glass in the sol state during the pressing used in amounts ranging from 5% to 20% by 25 operation I have found that by incorporating volume of the solution. It will be understood with the gelatine casein Small ammmt 0f that the monoacetyl diglyceryl ether may be subceltain 0f the high boiling solvents which are stituted in the formula given for the diglyceryl miscible with water, and at the same time, are ether using Similar propgrtions 311 compatible with the adhesive have some 111 using the cement, the solution is preferably acitlon on the plastic the mculty as to applied to the faces of the glass sheets in a very adheswn q m In the dmWIPg: thin coating by a spraying operation similar to The figure lsanenlarged sectional vlew through that commomy used in applying a gelatin 501w plate embmg the mventmn' tion to glass. After the cement coatings are dry Referring to the drawlng, i, l are glass sheets, to much and Sight, the Sheets of glass and cenu 2 isa sheet of cellulose nitrate plastic and 3 3 lose nitrate are assembled and laminated by the are coats or films of cement, such as gelatin or use of heat and pressure casein in which are incorporated the solvent m t I I which makes the adhesive effective with cellulose 0 mm 40 t t plastic having a large content of liquid A plate of laminated glass comprising a 40 plasticizer possessing the characteristics of low pm of glass sheets i an mtel'posed Sheet 01 water solubility. plasticlzed cellulose nitrate which is water re- An example of a nitrocellulose formula having Penent and has high Strength at low temperalarge t t, of liquid plasticizer of low water tures, and a layer of cement between the opposing faces of the glass and plastic sheets comsolubmty and low freezing point is as follow prising a water soluble cement and a high boiling 5 Cellulose nitrate solvent from the group consisting of monoacetyl Dibutyl Phthalate diglyceryl ether, and diglyceryl ether.

Other plasticizers having similar properties A plate of laminate? glass comprismg pair so which might be substituted in the above formula glass Sheets with an mtermsed Sheet Plas- 50 are dimethyl phthalate, diethyl phthalate, diam; ticized cellulose nitrate which is water repellent phtllalate, triacetin, tricresyl phosphate and t i. and has high strength at low temperatures, and phenyl hospheta' It will he understood that a layer of cement between e pp sin faces of these plasticizers may be used alone or with other the glass and plastic sheets comprising gelatin to members of the group, and that the amount of and a high boiling solvent from the group consisting of monacetyl diglyceryl .ether and diglyceryl ether. 3

3. A plate of laminated glass comprising a pair of glass sheets with an interposed sheet of plasticized cellulose nitrate which is water repellent and has high strength at low temperatures, and a layer of cement between the opposing faces of the glass and plastic sheets comprising casein and a high boiling solvent from the group consisting of monoaoetyl diglyceryl ether and diglyceryl ether.

4. A plate of laminated glass comprising a pair of glass sheets with an interposed sheet of ce1Iulose nitrate plastic having a plasticizer oi the group consisting of dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diamyl phthalate, triacetin, trlcresyl phosphate and triphenyl phosphate, and a layer of cement between the opposing faces of the glus and plastic sheets comprising a water soluble cement and a high boiling solvent from the group consisting of monoacetyl diglyceryl ether and digly ceryl ether.

JOHN c. ZOLA. 

